PROTON USA CORP Thermal Oil Boilers designs and constructs multi-stage boilers for greater fuel efficiency. Available to operate with gaseous fuels (natural gas and propane), liquids (diesel, fuel oil), and solids (coal and biomass). They are built vertically when space is limited or horizontally for ease of maintenance and are delivered as a package, with all required auxiliary equipment for reliable operation. Sizes available range from 50,000 Kcal/h to 5,000,000 Kcal/h. The use of thermal oil offers the following advantages: temperatures up to 350°C in the liquid phase at low pressure, operation in a closed circuit without the need for fluid replenishment or pretreatment, and operation without scaling issues.